Effects of the functionality of polyol in rigid polyurethane foams

Lim, Ho Sun; Kim, Sung Hee; Kim, Byung Kyu

doi:10.1002/app.28571

Cited by 21 publications

(7 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many researchers have extensively studied to improve thermal insulation property of PUF by reducing cell size and improving uniformity of cell morphology in the foams. [7][8][9][10][11][12][13][14][15][16][17][18][19][20] The PUF is based on the reaction of a diisocyanate with a polyol. The reaction is exothermic and the reaction heat can be used to form a cellular structure by evaporating the physical blowing agents such as trichlorofluoromethane (CFC) and HCFC.…”

Section: Introductionmentioning

confidence: 99%

Effects of nucleating agents on the morphological, mechanical and thermal insulating properties of rigid polyurethane poams

Kang

Kim

et al. 2009

Macromol. Res.

View full text Add to dashboard Cite

This study examined the effects of liquid and solid additives on the morphological, mechanical and thermal insulating properties of rigid polyurethane foams (PUFs). The PUFs synthesized with tetramethylsilane (TEMS) as a liquid-type additive showed a smaller average cell size and lower thermal conductivity than those with the aerosil 200 and clay 30B as solid-type additives. When TEMS was added, the average cell size of the PUF became more uniform and finer due to the reduced surface tension of the polymer solution, which increased the nucleation rate and number of bubbles produced and reduced cell size. The PUFs with TEMS showed the highest closed cell contents among the PUFs prepared using TEMS, aerosil 200 and clay 30B. This suggests that the insulation properties of PUF can be determined by both the size of the cell structure and the amount of closed cell contents in the system. The compression and flexural strengths of the PUF increased slightly when the aerosil 200, clay 30B and TEMS were added compared those of the neat PUF. The reaction profiles of the PUFs showed a similar gel and tack free time with the reaction time among the PUFs synthesized with three different additives and neat PUF. This suggests that the nucleating additives used in this study do not affect the bubble growth of the chemical reaction, and the additives may act as nucleating agents during the formation of PUF. From the above results of the cell size, thermal conductivity, closed cell contents and reaction profile of the PUFs, liquid-type nucleating agent, such as TEMS, is more effective in decreasing the thermal conductivity of the PUF than solid-type nucleating agent, such as aerosil 200 and clay 30B.

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of nucleating agents on the morphological, mechanical and thermal insulating properties of rigid polyurethane poams

Kang

Kim

et al. 2009

Macromol. Res.

View full text Add to dashboard Cite

show abstract

“…Moreover, the porous structure of polymer foams limits the distribution of fillers in the cell walls and cell struts to form effective reinforcing networks . In the literature, several processing techniques have been introduced extensively to improve the thermal insulation and mechanical properties of PUF by reducing cell size and improving the uniformity of the morphology in the PUF …”

Section: Resultsmentioning

confidence: 99%

Effects of raw and poly(propylene oxide) grafted nanosilica on the morphology and thermal and mechanical properties of polyurethane foam

Gao

Chen

Liang

et al. 2015

J of Applied Polymer Sci

View full text Add to dashboard Cite

Poly(propylene oxide) (PPO)-grafted nanosilica (NS)/polyurethane foam (PUF) composites were synthesized by a ringopening polymerization catalytic process and reaction-molding technology. The raw NS and PPO-NS were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and transmission electron microscopy. Scanning electron microscopy, dynamic mechanical analysis, and compressive strength tests were used to compare the morphology and thermal and mechanical properties of the PPO-NS/PUF and raw NS/PUF composites with a series of filler contents. The PPO-NS/PUF composites generally exhibited better morphology, thermal and mechanical properties than raw NS/PUF composites. Moreover, the PPO-NS/PUF composites with lower contents (0.5, 1 php) of filler showed even higher mechanical reinforcement than that with higher contents (1.5, 2 php) of filler, which was caused by the interaction between additives and PUF matrix.

show abstract

“…[18][19][20][21] In case of the said water blown PU foams, water is considered a chemical blowing agent (CBA) generating carbon dioxide by the blowing reaction. [13][14][15][16] Physical co-blowing agents (PBA), such as pentane, may be also utilized. Dissolved in the liquid state in the components prior to mixing, PBA evolve in the gaseous state as a consequence of the exothermicity of the reactions and inflate the bubbles formed by the primary blowing agent.…”

Section: Introductionmentioning

confidence: 99%

The effect of organofluorine additives on the morphology, thermal conductivity and mechanical properties of rigid polyurethane and polyisocyanurate foams

Brondi

Maio

Bertucelli³

et al. 2021

Journal of Cellular Plastics

View full text Add to dashboard Cite

This study investigates the effect of liquid-type organofluorine additives (OFAs) on the morphology, thermal conductivity and mechanical properties of rigid polyurethane (PU) and polyisocyanurate (PIR) foams. Foams were characterized in terms of their morphology (density, average cell size, anisotropy ratio, open cell content), thermal conductivity and compressive as well as flexural properties. Based on the results, we observed that OFAs efficiently reduced the average cell size of both PU and PIR foams, leading to improved thermal insulating and mechanical properties.

show abstract

Effects of the functionality of polyol in rigid polyurethane foams

Cited by 21 publications

References 17 publications

Effects of nucleating agents on the morphological, mechanical and thermal insulating properties of rigid polyurethane poams

Effects of nucleating agents on the morphological, mechanical and thermal insulating properties of rigid polyurethane poams

Effects of raw and poly(propylene oxide) grafted nanosilica on the morphology and thermal and mechanical properties of polyurethane foam

The effect of organofluorine additives on the morphology, thermal conductivity and mechanical properties of rigid polyurethane and polyisocyanurate foams

Contact Info

Product

Resources

About